/Engine/Source/Runtime/ClothingSystemRuntimeCommon/Public/PointWeightMap.h
A mask is simply some storage for a physical mesh parameter painted onto clothing. Used in the editor for users to paint onto and then target to a parameter, which is then later applied to a phys mesh
struct FPointWeightMap
bool
bEnabled
Whether this mask is enabled and able to effect final mesh values
uint8
CurrentTarget
The currently targeted parameter for the mask,  EWeightMapTargetCommon
FName
Name
Name of the mask, mainly for users to differentiate
TArray< float >
Values
The actual values stored in the mask